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mutableIdentity(Ring,ZZ) -- make a mutable identity matrix

Synopsis

Usage:
mutableIdentity(R,nrows)
Function: mutableIdentity
Inputs:
- R, a ring
- nrows, an integer
Outputs:
- a mutable matrix, an nrows by nrows mutable identity matrix filled with elements of the ring R
Optional inputs:
- Dense => default value true, whether the encoding of the matrix should be dense or not: see MutableMatrix

Description

i1 : m = mutableIdentity(QQ,10)

o1 = | 1 . . . . . . . . . |
     | . 1 . . . . . . . . |
     | . . 1 . . . . . . . |
     | . . . 1 . . . . . . |
     | . . . . 1 . . . . . |
     | . . . . . 1 . . . . |
     | . . . . . . 1 . . . |
     | . . . . . . . 1 . . |
     | . . . . . . . . 1 . |
     | . . . . . . . . . 1 |

o1 : MutableMatrix

i2 : m_(5,5) = 11/13

     11
o2 = --
     13

o2 : QQ

i3 : m

o3 = | 1 . . . . .     . . . . |
     | . 1 . . . .     . . . . |
     | . . 1 . . .     . . . . |
     | . . . 1 . .     . . . . |
     | . . . . 1 .     . . . . |
     | . . . . . 11/13 . . . . |
     | . . . . . .     1 . . . |
     | . . . . . .     . 1 . . |
     | . . . . . .     . . 1 . |
     | . . . . . .     . . . 1 |

o3 : MutableMatrix

See also

mutableMatrix -- make a mutable matrix